(1) Field of the Invention
The present invention relates to an image forming apparatus which ejects ink in an ink cartridge through a nozzle array to form an image on a recording medium, more specifically, to an image forming apparatus comprising a cover which is opened and closed for the replacement of an ink cartridge.
(2) Background Art
Image forming apparatuses comprising ink cartridges which put and retain ink inside thereof, recording heads which eject ink contained in the ink cartridges through nozzle arrays so as to form images on recording mediums, and covers which are opened and closed for replacement of ink cartridges, have all been conventionally known. In the above-mentioned image forming apparatus, ink in the ink cartridge is ejected through the nozzle array of the recording head depending on image data or the like, whereby an image can be formed on the recording medium. Also in the above-mentioned image forming apparatus, when the ink in the ink cartridge is consumed, the cover is opened for replacement of the ink cartridge and is closed again in order to perform the image forming operation.
When the ink cartridge is replaced by a new ink cartridge, it is required to purge the ink within the ink cartridge to the nozzle array of the recording head and to perform maintenance so as to prepare the system for image forming. However, when only some of the ink cartridges are replaced, it is not preferable to perform the same maintenance for each nozzle array corresponding to all of the ink cartridges. For example in a multicolor image forming apparatus, which comprises a plurality of nozzle arrays and ink cartridges, when just a few of the ink cartridges are replaced, it is not preferable to perform the same level of maintenance on the nozzle arrays corresponding to the unreplaced ink cartridges as in the case of nozzle arrays corresponding to ink cartridges replaced by new ink cartridges. Using the same level of maintenance would be a waste of ink.
Therefore, in a computer-connected image forming apparatus, it is desirable that after selecting a replacement mode for the ink cartridges, a user is asked via a computer or other interface whether or not an ink cartridge has actually been replaced (for example, see Publication of Unexamined Japanese Patent Application 2001-232785).
However, unless the query of whether or not the ink cartridge has been replaced is made with the appropriate amount of timing, there is a possibility that the query process may timeout while the user is performing the replacement. And without closing the cover of the image forming apparatus, the user may inadvertently input the termination of the replacement process, and consequently the maintenance may be performed directly.